Thread-in drain for lavatories.

ABSTRACT

A thread-in drain for lavatories includes a flanged and threaded pipe inserted into the lavatory drain waste hole from above said hole for connection to plumbing below said hole. Said flange is secured to the inside of the vessel by tightening a nut and washers threaded onto said pipe from below the vessel. Cross-hairs found in traditional lavatory drains are eliminated. A plurality of closures and grates and screens can be introduced and fixed onto the drain by threading an attached male thread ring on the bottom of said introduced piece into a female thread groove on the upmost interior of said threaded pipe. Said thread-in drain allows for removal and sterilization of said introduced piece. Said thread-in drain allows for access to the interior of the drain by cleaning devices. Said thread-in drain allows for uniform distribution of anti-microbial coating in the interior of said drain.

CROSS-REFERENCE TO RELATED APPLICATIONS

No cross reference is made to other applications.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OF DEVELOPMENT

No Federal Government support was received in the development of this Invention.

SEQUENCE LISTING, TABLE, OR COMPUTER PROGRAM LISTING

No sequence listing, table, or computer program is attached or accompanies this Application.

PATENTOR

Christopher Adam McLeod is the Sole Inventor of this Utility.

FIELD OF THE INVENTION

This Invention relates to a drain for a lavatory.

BACKGROUND OF THE INVENTION

A sink, herein “lavatory”, is drained of water by a “drain” assembly. The upper portion of this assembly consists of a “closure” or a “grate” or a “screen”. The lower portion of the drain invariably consists of a flanged pipe with male thread along the exterior of the length of said pipe. A nut and plurality of washers may be threaded up the pipe after said flanged pipe has been inserted into lavatory drain hole from above. This serves to seal and tighten the flanged drain pipe to the lavatory. Common drain “closures” include rubber stoppers, spring loaded devices, and pin capture devices. Common drain “grates” include a grid, or daisy pattern perforated plate. Grates are permanently integrated onto the top of the flange and cannot be removed. Common “screens” include circular non-splash domes suspended above the flange by a variety of devices. A “tailpiece” is an interstitial length of tube or pipe that connects the lavatory drain to further plumbing, usually a trap. The tailpiece can be attached to the lavatory drain by mounting methods including soldering and welding and gluing, or by cinching a nut against an optional flange on the top of the tailpiece and threading that nut onto the drain pipe male thread, or by threading the tailpiece and threading that into the bottom of the lavatory drain pipe wherein a complementary female thread has been provided. “Tube” is a hollow cylinder categorized by its outside diameter. “Pipe” is a hollow cylinder categorized by its internal diameter. “Cross hairs” are a common feature to all lavatory drains consisting of a horizontal cross of material forming a barrier to solids falling down the drain. Said cross-hairs are commonly located at a height within the interior of the lavatory drain assembly drain pipe such that the cross-hairs also form a support for said drain closures. “Introduced portions” are fittings such as drain closures or grates or screens that provide functionality within the lavatory and are attached to some part of the lavatory drain. “Crumb cup” refers to a perforated cup.

In the early days of plumbed lavatories, a rubber stopper was stuck into a lavatory drain to retain water in a lavatory. Since “stopper” implies a resistance fit, this terminology has evolved to “drain closure” to also include categories of devices that effect closure with a sealing “gasket” that lies atop said drain pipe flange inside the vessel to effect closure. Alternatively, an o-ring can seal against the interior of the threaded pipe portion of the drain. The “open” position of a drain closure must include a mechanism whereby, when in open position, the drain stays open in opposition to the force of the head of water within the vessel that naturally operates to close the drain and seal the gasket, or-ring or other annular seal.

More advanced stopper drain closures include Fairchild (U.S. Pat. No. 1,300,593: Apr. 15, 1919) and Leduc (U.S. Pat. No. 1,403,423: Jan. 10, 1922). These devices indicate a rudimentary initiative to include new convenient functionalities of a drain closure. Here, the plugs have features to prevent removal. These patents illustrate the concept of “introduced portions” here comprised by drain closures.

A number of patents describe drain closure assemblies including a spring to enable an easy transition from open position of the drain to closed position of the drain. Watts (U.S. Pat. No. 4,720,877: Jan. 26, 1988) patented the “push pull” drain which maintains an open position using a sprung ball bearing. The advantage of this design is that the fraction of the strainer volume occupied by the “stem” of the “push pull” is small and interferes less with drain flow when open. The disadvantage of small springs used is the eventual failure to maintain an open position against the head pressure of liquid being drained from the vessel. Significant here is the support of the push pull by the cross-hairs deep in the interior of the lavatory drain pipe.

Kivela (U.S. Pat. No. 2,915,762: Dec. 8, 1959) describes a device which makes use of a coil spring centered around the “stem” axis. Such an open spring device is easily fouled by hair and other debris. The spring longitudinal to the “stem” axis, when combined with a catch system, resulted in the evolution of two standard drain closures. The first is “pop up” using a large axial spring and a ballpoint pen clicker barrel, as in Petursson (U.S. Pat. No. 3,366,980: Feb. 6, 1968). The other is the unpatented “clicker” device which uses a planar track instead of the pen clicker barrel to maintain an open position in opposition to the head of draining liquid. Both of these devices occupy a large fraction of the volume within the “strainer”, potentially slowing liquid drainage from the vessel. Both closures rely upon cross-hairs for support.

Hobbs (U.S. Pat. 5,881,397: Mar. 16, 1999) describes a device which avoids all springs and instead relies upon lifting and turning of the “stem” axis to capture a projecting pin. While this design avoids the shorter life span of springs and the volume occupied by sprung devices, it is delicate in that the user of a bath can ruin the device by simply standing upon it and breaking the pin. The pop-up and clicker closures also rely upon the cross-hairs within the lavatory drain pipe for support. Grates are directly fixed to the flange of the lavatory drain assembly. Screens hitherto have been attached to grates in unpatented lavatory drains by Delta, exemplifying the potential for combination of more than one introduced portion. Again, the cross-hairs are used for support.

The cross-hairs located in a horizontal plane within the lavatory drain assembly drain pipe both prevent solid matter from being washed down the drain and form a support for the drain closures described above. Grates perform the same function where drain closure is not required. Cross-hairs and grates pose contamination problems particularly significant for infection control environments like hospitals:

(1) Cross-hairs and grates prevent passage of cleaning brushes. (2) Cross hairs and grates present a plurality of niches for microbes to harbour. (3) Cross hairs and grates impede uniform coating of anti-microbial coatings within said drain pipe. (4) Supporting drain closures screens deep with the drain poses challenges for the regular removal and sterilization of said drain closures. Grates are simply impossible to remove.

These four impediments to microbial control in lavatory drains can be rectified by eliminating any cross-hairs or grates. This leaves the challenge of how to provide support for drain closures or drain grates or drain screens, or any combination of said three features. All introduced portions consisting of a drain closure or grate or screen can be instead accommodated in a thread-in drain by simply changing the support for the various devices from the cross-hairs or flange to a male thread ring located on the bottom of the introduced portion. Said male thread ring is threaded into a female thread groove located to the interior of the topmost portion of the drain pipe. The closure or grate or screen or combination thereof is attached to the male thread ring.

SUMMARY OF THE INVENTION

Accordingly, it is an objection of this invention to at least partially overcome some of the disadvantages of the prior art.

In a preferred embodiment, a domed anti-splash screen is mounted on legs connecting it to a male thread ring. This male thread ring is sized and threaded to be threaded into a complementary female thread groove in the interior of the topmost portion of the drain pipe in the flanged pipe portion of the drain assembly. In a similar fashion, grates can be threaded into the top of the receiving female threaded flanged drain pipe. In a similar fashion, drain closures can be threaded into the top of the receiving female threaded flanged drain pipe. Although simple, this assembly enables all four of the microbial control functionalities to be realized; namely:

(1) By removing the thread-in introduced portion of the drain assembly comprising a closure, grate, or screen, cleaning brushes can penetrate fully to the bottom of the drain pipe without impediment. (2) A completely open interior diameter of the lavatory drain minimizes niches for microbial growth. (3) A completely unimpeded cylindrical cavity allows for uniform distribution of anti-microbial coating on the interior surface of the lavatory drain. (4) Having introduced portions of the drain assembly thread into the top of the drain pipe allows for easy and complete removal of these introduced pieces for sterilization.

In a preferred embodiment, the flanged drain pipe is first fed through the drain waste hole in the bottom of the lavatory. The flange on the drain pipe allows the strainer to hang freely on the lavatory interior. Underneath the vessel a plurality of washers is threaded onto the threaded drain pipe and secured with a nut for waterproof attachment of the drain to the lavatory. A domed anti-splash screen attached by legs to a male thread ring for threading into the complementary female thread groove in the interior of the topmost portion of the drain pipe completes the screen embodiment of this invention.

Further aspects of the invention will become apparent upon reading the following detailed description and drawings, which illustrate the invention and preferred embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, which illustrate embodiments of the invention:

FIG. 1 is an exploded isometric view of the thread-in drain assembly in accordance with the screen embodiment of the present invention, showing optional crumb cup;

FIG. 2 a is a top view of the thread-in drain in accordance with the screen embodiment of the present invention;

FIG. 2 b is a side sectional view of the thread-in drain in accordance with the screen embodiment of the present invention, showing the seating of the optional crumb cup.

FIG. 3 is a side view of the thread-in drain, showing the lavatory or sink position, in accordance with the screen embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to FIG. 1, an exploded isometric view of the thread-in drain assembly in accordance with the screen embodiment of the present invention, showing optional crumb cup. The lavatory drain in its screen embodiment includes a dome screen 1, supporting legs 2, and a male thread ring 3. Said thread ring threads into a female thread groove 5 to allow the attachment of the introduced portion to the flanged drain pipe. An optional crumb cup 4 sits within the interior of the drain pipe. A flange 6 anchors the drain pipe to the sink and a female thread 7 is available to nuts of various functions.

Referring now to FIG. 2 a, the thread-in drain is shown in a top view of the screen embodiment. The flange 6 of the drain pipe is visible.

Referring now to FIG. 2 b, a side sectional view of the thread-in drain in its screen embodiment. The screen 1 is attached by legs 2 to a male thread ring 3 to be threaded into a female thread groove 5 on the inside of the topmost internal portion of the drain pipe 9. An optional crumb cup 4 is illustrated. An optional internal thread 10 for the attachment of a threaded tailpiece is illustrated. An internal restriction 8 forms a ledge upon which the optional crumb cup can sit.

Referring now to FIG. 3, a side view of the lavatory showing the resting of the drain flange 6 atop the sink or lavatory surface 11. 

The following claims are made about the Invention described in this Application:
 1. This thread-in lavatory drain consists of a female thread groove in the interior of the topmost portion of a flanged drain pipe into which an introduced portion is attached by means of the threading in of a complementary male thread ring to which said introduced portion is affixed.
 2. Said introduced portion can be a drain closure, a grate, or a screen.
 3. Said thread-in lavatory drain contains no cross hairs.
 4. Said thread-in lavatory can accommodate a crumb cup within the interior of the drain pipe. 